Integral formed oil column extender for hydraulic lash adjuster

摘要

A hydraulic lash adjuster for an internal combustion engine, and a method of its construction is disclosed. The lash adjuster has a cylindrical follower body in which a tubular plunger is slidingly disposed. The plunger cooperates with the follower body to define a high pressure chamber therebetween which is supplied with fluid through a valved port. A low pressure chamber which operates to supply fluid to the high pressure chamber through the valved opening, is defined by an axial passage through the plunger. Fluid flows into and out of the low pressure chamber through a port in the wall of the plunger. Intermediate of the port and the valved opening is a radially inwardly extending annular shelf which is integral formed with the axial passage of the plunger using a mechanical shaving step to plow a portion of the plunger material from the wall of the axially extending passage. The annular shelf operates as a baffle to prevent loss of fluid from the low pressure chamber when the hydraulic lash adjuster is installed at an angle from vertical.